National Hot Dog Day is here on July 23, which naturally got us thinking of all the wondrous ways weiners are consumed around the world. The Seattle Dog is smothered in cream cheese, the Mexican Sonora dog is wrapped in bacon, and the Japanese octodog looks like an octopus, obviously.

Wait, what?

It's not uncommon in Japan to find a hot dog shaped like an octopus in your bento box. But if you want to make one yourself without leaving the country, it's ridiculously simple --...